The present invention relates to an apparatus for machining an elongated workpiece such as a cylinder and a roller.
An elongated workpiece such as a roller for a printing machine is heavy and also large in size. Further, such a workpiece needs to be subjected to turning processing, milling processing and boring processing. When such a workpiece is machined with the use of a machining center in each process step, its setup takes time and a load on each process is increased. In this case, the workpiece is first suspended between a spindle and a tailstock of a workpiece machining apparatus by a crane. Subsequently, the workpiece is positioned by inching operation of the crane, and then held by the spindle and the tailstock. The workpiece is carried out of the apparatus after the machining and is manually transported to a machining machine for a subsequent process. In the subsequent process, the workpiece is again placed in the machining machine and removed from the machining machine.
As described above, when an elongated and heavy workpiece such as a roller for a printing machine is subjected to turning processing, milling processing and boring processing, the positioning of the workpiece between the spindle and the tailstock by inching operation of the crane is troublesome.
Japanese Laid-Open Patent Publication No. 62-292351 discloses a grinding machine provided with a pair of rests for supporting a workpiece between a work head (a spindle) and a counter head (a tailstock). Although Japanese Laid-Open Patent Publication No. 62-292351 discloses supporting of the workpiece by a pair of rests, the publication does not disclose that the workpiece is moved between the spindle and the tailstock by both rests.